system (systick related)

system.c

@@ -0,0 +1,35 @@
+#include "system.h"
+#include <libopencm3/cm3/systick.h>
+#include <stdint.h>
+
+volatile uint64_t ticks = 0;
+
+void sys_tick_handler(void) { ticks++; }
+
+uint64_t get_ticks(void) { return ticks; }
+
+void systick_setup(void) {
+    // systick_set_frequency(1000, 72000000);
+    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
+    systick_set_reload(72000000 / 1000 - 1); // 1ms tick
+    systick_clear();
+    systick_interrupt_enable();
+    systick_counter_enable();
+}
+
+void sys_tick_setup(void) {
+    ticks = 0;
+    // rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE16_72MHZ]);
+
+    // systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);
+    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
+
+    // systick_set_reload(8999);
+    systick_set_frequency(1000, 72000000);
+    systick_clear();
+
+    systick_interrupt_enable();
+    systick_counter_enable();
+
+    return;
+}

system.h

@@ -0,0 +1,6 @@
+#pragma once
+#include <stdint.h>
+
+void sys_tick_handler(void);
+uint64_t get_ticks(void);
+void systick_setup(void);